Motor-control system



MOTOR GONTROL SYSTEM Filed June 25, 1927 2 Sheets-Sheet 1 .qll v3 84 INVENTOR 90 Frank E.Lew'|s.

ATTORNEY Aug. 20, 1929. F. E. LEWIS 1 ,725,090

I MOTOR CONTROL SYSTEM Filed June 25, 1927 2 Sheets-Sheet 2 INVENTOR FranK E. Lewls ATTORNEY Patented Aug. 20,

UNITED STATES PATENT, OFFICE.

FRANK E. LEWIS, OF EAST PITTSBURGH, PENNSYLVANIA, ASSIGNOB TO WESTING- HOUSE-ELECTRIC & MANUFACTURING COMPANY, A CORPORATION OF PENNSYL- VAN IA.

MOTOR-CONTROL SYSTEH.

Application and June as, 1927. Serial No. 201,410.

My invention relates to motor-control systems and has particular reference to control systems for elevators, hoists and similar apparatus.

Anobject of In invention is to provide a control system or elevators wherein the starting of the car is under the control of an attendant on the car and the stoppin of the car is under the control of persons desiring to to use the car.

Another ob'ect of m invention is to provide a control system or elevators wherein the car is automatically stopped in response to push-buttons operated by persons desiring to use the car, the buttons being either on the car or at the landings and wherein the car is started, after each stop, by a manual operation performed by an attendant on the car.

Another object of my invention is to provide a control system, as described in the preceding paragraph, wherein the stopping of the car is under the control of relays operated by the persons desiring to use the car and wherein the relays are maintained operative until after the car leaves the floor for which such relay has been operated.

' Anotherobject of my invention is to pro vide a control system for a bank of elevators of the type wherein the stopping of the cars is under the control of persons desiring to use the elevators, wherein the starting of each car is under the control of an attendant on the car and wherein the first car to ap- 38 proach a floor at which a passenger desires to use the elevator will be caused to stop.

Another object of my invention is to rovide a control system of the type described in the preceding paragraph, wherein floor 40 lanterns or other signals will be caused to be operated as the car ap roaches the floor preparatory to stopping t ereat.

1 Another object of my invention is to provide a control system for elevators wherein fioor lanterns will be illuminated at the floors at which the car is to stop, only at such times as the car is within the distance required for deceleration in order to stop at i the corresponding floor.

Another ob'ect of my invention is to provide a contro system for elevators of the high-speed type wherein the elevator is prevented from attaining its high-speed operation when making a run of only a single floor.

' My invention is described with reference to the accompanying drawing wherein Figures 1 and 2 are jointly dia rammatic views of the control circuits an apparatus embodied in my invention, as applied to two elevator cars. a

Referring to the drawing, an elevator car C, suspended in the usual manner by a cable CA, is illustrated as operating between a plurality of floors respectively designated as 1st floor, 2nd floor, 3rd floor and 4th floor. \Vhile only four floors are'shown, it is ob vious that my system may be applied to elevators operating between any number of floors. A pair of push buttons are mounted at each of the landings, intermediate the terminal floors, one for up travel and one for down travel. The u and down buttons for the second oor are respectively designated as 2U and 2D, while those for the third floor are designated as 3U and 3D.

Associated with the respective ush-but tons are push-button relays 3UR, 3 R 2UR and 2DR, respectively. Also associated with the respective push-buttons are reset relays 3US, 3DS, QUS and QDS, respectively, for resetting calls registered by actuation of push button relays 3U R, etc., by restoring these relays to normal when such calls are answered, as well as'restoring the signals, hereinafter described, to their normal deenergized condition.

Push-buttons C2 and C3 for the respective intermediate floors are mounted on the car C. A floor selector FS for car C is mounted at any suitable point, for example, in the pent-house or in the elevator shaft, and is provided witha set of up contact segments U and a set of down contact segments D, mounted upon a suitable base (not shown) and traversed by a movable arm A I operable in accordance with movements of the elevator. The movable arm A carries a series of brushes, AU, BU, etc., adapted to bridge the spaces between the contact segments. The floor selector FS may be similar to those ordinarily used in elevator Sig-. nal systems, wherein the movable arm is operated by a screw S driven by some part'of the elevator-operating mechanism for car C. The frictional engagement between the arm A and the screw S causes the arm to bear upon one of the sets of contact segments and to be lifted from engagement with the other set of contact segments when the elevator is travelling in one directiqrij' and the reverse of this arrangement obtains when travelling in the opposite direction.

The arrangement of the contact segments on the floor selector comprises a grouping of the segments for each direction into four groups, (each group bridged by suitable brushes on the arm A), respectively designated as AU, BU, CU and EU. The group AU controls the automatic stopping of the car from the floor push-buttons 2U and 3U and includes a continuous contact strip AU and a contact segment for each of the floors served by the elevator, in the instance shown being designated as 3AU and 2AU. The group BU controls the stopping of the car from the car push-buttons C2 and C3, and comprises a continuous strip EU and segments 3BU and 2BU. The group CU controls the resetting of the push-button relays 2UR and 3UR and comprises a continuous strip CU and segments 3CU and 2CU. The EU group comprises two contact segments of equal length for each of the floors and respectively designated as 3EU, 2EU and 4EU.

This group, it will be noted, includes a set of contact segments for the terminal floor in.

addition to those) for the intermediate floors. The function of this group of contacts is to operate the floor lanterns L2U, and L3U, etc.,

ordinarily used to indicate to waiting pas sengers which of the elevators in a bank is to stop for them.

The down side of-the floor selector FS comprises a duplicate of the groups of up contact members previously described, except for a reversal of the order of the contact members and a slight change in the relative positioning of the various groups to compensate for the difi'erent direction in which the car approaches the floor.

A series of dotted lines numbered, respectively, 1', 2, 3', and 4 are shown upon the floor selector FS to indicate the position of the movable arm with reference to the contact segments, which position corresponds to the position of the elevator with reference to the floors between which it operates.

The control system for the elevator is of the automatic inductor-landing type described in the copending application of E. M. Bouton, Serial No. 731,921, filed Aug. 14, 1924, and assigned to the Westinghouse Electric and Manufacturing Company comprising a suitable motor (not shown) controlled through the agency of an up direction switch 1 and a down direction switch 2, operated by a car switch CS mounted upon car C. The operation of the elevator-control system may be best described with reference to an assumed operation.

ductors 10 and 11, contact members of a door relay 12, conductor 13, the coil of up direction switch 1, conductors 14 and 15, contact members 16 and 17 bridged by the contact segment 17 of the car switch CS, and con ductors 19, 20 and 21 to line conductor L2. Up direction switch 1 operates to close its contact members 16 which are in circuit with the elevator hoisting motor (not shown), and the car will be caused to start upwardly.

As the car starts upwardly in response to the operation of the up direction switch 1, a circuit is completed for a speed relay 22 which operates to insert resistance in circuit with the motor field windings, or in any other suitable manner, to cause the elevator to operate at high speed. This circuit extends from line conductor L1 through conductors 10 and 23, the contact members of a switch UL (preferably of. the limit-switch type), conductor 24, contact members 1a, conductor 25, normally closed contact members 26?) of a relay 26, conductors 27 and 28, the coil of the speed relay 22, conductors 29 and 30, contact members 31a of a speed-responsive relay 31, conductor 82, thence, in series, through the normally closed contact members 33b, 34b, 35b, 36b, and thence by way of conductors 37 and 21 to line conductor L2.

Connected in parallel relation to the coil of the relay 22 is the coil of a landing switch 38. This landing switch may be of the inductor-relay type or of the type commonly used in connection with push-button-controlled elevator systems, comprise a contact member 38a which may be moved to closedcircuit position either by the energization of a coil 38?; or by the depression of a cam roller 380. The landing-switch structure is mounted upon some suitable portion of the elevator car C, such as indicated by reference numeral 38"upon the top of the car C in the drawing. The cam roller 38G coacts with a plurality of earns 39, 40, 41, 42, 43 and 44 mounted adjacent to the several floors served by the elevator. The usual operation of the switch 38 is such that the coil is energized at all times except when the car is to make a stop at a floor and the speed switch has been opened to slow down the car. As indicated by the parallel connection of the coils of the speed'switch 22 and the landing'switch 38, the speed will be reduced and. the roller 38C will drop upon one of the cams 39, 40, 41, 42, 43 and 44, dependent upon the floor approached by the elevator. The effect of the engagement of the cam and roller will be to maintain the landing-switch contact members 38a closed until the roller 38C passes off the cam, at

which time the contact members 380. will be separated.

The contact members 38a complete a selfholding circuit for the direction switch 1 or switch 2 (dependent upon thedirection in which the car is travelling), maintaining the elevator motor operative until the car arrives at an exact level with the floor. This circuit may be traced from line conductor L1, through conductors 10 and 11, contact members of the relay 12, conductor 13, coil of the relay 1, conductors 14 and 45, contact members 1c, conductors 46 and 47, contact members 38a of the landing switch 38, and conductors 48 and 21 to line conductor L2. As soon as this self-holding circuit is complete, the attendant on the car may return the car switch OS to its central or off position, and the car will continue to move upwardly.

Assume now that a person desiring to travel upwardly from the second floor operates the push-button 2U at that floor. The operation of this button will complete a circuit for the push-button relay 2UR extending from line conductor L1 through con ductor 50, contact members of push-button 2U, conductor 51, the coil of relay 2UR, conductor 52, contact members or reset relay 2US and conductors 53 and 21 to line conductor L2. Push-button relay 2UR completes a self-holding circuit which extends from line conductor L1 through conductor 54, contact members 2URa and conductor 55 and thence through the coil 2UR to line conductor L2, as previously described. Contact members 2URb partially complete a circuit for the up floor lantern L2U for the second floor, and contact members 2URO partially complete a circuit for the relay 36.

As the car starts upwardly from'the first floor, the brush AU of the floor selector arm A is in engagement with the contact strip AU and the contact segment 2AU. Thus, a circuit for the relay 36 is immediately closed, upon the operation of the relay 2UR, extending from line conductor L1 through conductors 54 and 56, contact members 2URO, conductors 57 and 58, contact segment 2AU, brush AU contact strip AU, conductor 59, the coil of relay 36, and conductors 60, 61 and 21 to line conductor L2.

The brush EU, at this instant, also connects the two contact segments 2EU, thus completing the circuit for the second floor up floor lantern L2U. This circuit extends from line conductor Ll through conductors 54, 56 and 65, contact members 2URb, conductors 66 and 67 contact segments 2EU,

conductor 68, floor lantern L2U, and conductors 69 and 7 0 to line conductor L2. The floor lantern is illuminated to indicate to the waiting passenger thatthe car associated with this lantern will be the one which will stop for him.

While only two elevators are shown, it is to be understood that my system is applicable to a bank of any number of elevators in which a set of floor lanterns, individual to each of the elevators, are usually provided. Thus, it is desirable to indicate which one of several elevators is to stop' at the floor. Itwill also be noted that the conductors 68 and 58 may be common to a number of elevators in the bank, as indicated by the arrow-heads placed upon the lower ends of these conductors.

The energization of the relay 36, as described, breaks the circuit for the speed relay 22 and the landing switch 38 by its contact members 36b, and closes a circuit energizing the slow-down inductor relays 71 and 72. This circuit extends from line conductor L1 through conductors 10 and 75, contact members 36a, conductors 76 and 77, the coil of the inductor relay 71, conductors 78 and 79, contact member 80 on the car switch CS and thence through the contact segment 17, contact member 18 of the car switch CS, and conductors 19, 20 and 21 to line conductor L2. v

The speed relay 22 is provided with a selfholding circuit extending from the coil 22, through conductors 29, 30 and 81, contact members 22w, conductor 82, normally-closed contact members 71' of the relay 71, the normally-closed contact members 130 of the relay 72, and conductors 84, 20 and 21 to line conductor L2. Thus, the opening of the contact members 366 will not cause the immediate deenelgization of the relay 22. However, as the car approaches the slowdown zone for the second floor, the inductor relay 71, now energized, passes an inductor plate and operates to open its normally closed contact members 71. The opening of the contact members 71' deenergizes the s eed relay 22 and the landing switch 38, t us reducing the speed of the car and permitting the roller 380 to be engaged by cam 40. As the car continues toward the second -floor, the roller 380 moves off the cam 40, and the car is brought to an accurate stop, level with the second floor.

It is desirable to have the floor lamp L2U, remain illuminated until the car starts to leave the floor. This is accomplished, in my system, by extending the floor-lamp contact segments BEU, 2EU etc. to a point which represents the position of the car at a level with the corresponding landing and by maintaining the push-button relay, associated with this floor, in operativecondition until the car leaves the floor. The restoring of the push button relay is accomplished by the energization of the associated reset relay. For example, in our assumed operation of the second floor up stop, the push-button relay 2UR remained energized through its self-holding circuit, leading through the reset relay 2US. The circuit for the relay 2US extends through normally closed contact members 315 of the speed-responsive rclay 31.

The relay 31 is connected across the armature MA of the hoisting motor (shown only as a circle with the reference character MA), and is designed to be picked up only at such times as the hoisting motor is operating at high speed but will remain energized until the car comes to a complete stop. Thus, as the car passes a floor for which a button has been operated, without stopping (such as when the button was actuated after the car had passed the beginning of the slow-down zone for that floor), the contact made by the brushes CU and the contact segment 2CU would not effect a restoration of the pushbutton relay. since the restoring circuit is held open by relay 31. The relay 2UR would then function to stop the next car to approach the floor.

\Vhen, however, the car stops at the floor (as in the assumed operation) and then restarts, the closing of the direction switch 1 or the direction switch 2 will energize the corresponding reset relay, since, at this time, the speed-responsive relay 31 has its contact members 316 closed. This circuit extends from line conductor L1 through conductors 86, and 88, coil of relay 2US, conductor 89, contact segment 2CU, continuous contact strip CU, conductor 90, contact members 111, conductors 91 and 92, contact members 31?), ind conductors 93 and 21 to line conductor The attendant on the car next opens the second floor door and the passenger enters the car. While the doors are open, the elevator car is prevented from starting by the deenergization of the relay 12, the circuit for which leads through the door and gate switch indicated by legends. When the attendant again closes the doors, the relay 12 is energized by way of a circuit which extends from line conductor L1 through conductor 186, the gate and door switches, conductor 187, coil of relay 12 and conductors 188 and 21 to line conductor L2. The -attendant may then again start the car on its upward movement by proper operation of the car switch CS, as described, before the 'start from the first floor. I

As the car starts upwardly from the second floor, the up direction switch 1 and the speed relay 22 will operate to start and speed up the elevator as previously described. The car will continue upwardly, stopping at the other floors for which, u buttons have been operated, as describe for the second floor stop. As the carapproaches its upper limits of travel, a cam 100 mounted on the elevator car will engage and open the contact members of the switch UL. The opening of switch UL will open the circuit to the up direction switch and to the speed switches to cause the car tos'top at the upper terminal,

independently of the operation of any pushbuttons at the terminal floor.

At the upper terminal the brush EU of the floor selector FS will complete a circuit for the floor lantern L4D extending from line conductor L1 through conductors 100' and 101, contact segments iEU, conductor 102, floor lantern L4D, and conductors 103 and to line conductor L2.

The attendant on the car now moves the car-switch handle CS to the right, completing a circuit for energizing the down direction switch 2, and the car starts downwardly in the manner'described for upward movement. 1 i 3 Assume that a passenger entering a car at the upper terminal or fourth floor desires to their depressed positions when operated by.

the attendant. The circuit for this coil extends from line conductor'Ll through conductors 10, 11 and 106, contact members 1070, conductors 108 and 109, the hold-down coil 105, and conductors 110, 20 and 21 to line conductor L2.

. The car proceeds downwardly until the brush BD of the movable arm A of the floor selector FS bridges the continuous contact strip BD' and contact segment 2BD. At this time, a circuit will be completed for the frelay 33, extending from line conductor L1 through conductors 10 and 120, contact members of push-button C2, conductors 121 and 122, contact segment 2BD, brushes BD, continuous contact strip BD', conductor 123, the coil of relay 33, and conductors 124, 61 and 21 to line conductor L2. The relay 33 energizes the inductor relay 72 by way of a circuit/which extends from line conductor L1 through conductors 10, 11, 75 and 125, contact members 33a, conductors 126 and 127, the coil of the inductor relay 72 and thence,

by way of conductor 128 and the central con-' tact-member of the car switch CS, to'line conductor L2, as traced for the inductor relay 71.

The car approaches the second floor and the inductor plate 129 operates relay 7 to open (by its contact members 130) the holding circuit for the down direction switch 2 in the same manner as described for the operation of the relay 71. The car is thus brought to a stop level with the second floor landing. After the exit of the passenger, the attendant again operates the car switch OS to cause the car to proceed on its downward trip, as previously described.

- Relays 26 and 107 are designated as up and down relays, respectively, and are controlled by a pair of limit switches UL and DL, engageable by cams 100 and 111, respectively, as the car approaches the upper and lower limits of travel. The function of these relays is twofold. The first function is to insure the deenergization of the holddown magnet coil 105 and the subsequent release of the push-buttons C2 and G3 on the car at the end of each up or down trip of the elevator. The second function is to prevent the car from travelling at high speed in the case of a reversal of the car before it has completed. a full up or down trip. The circuits for the speed relay 22 and the landing switch 38 pass through normally closed contact members of the relays 107 and 26 (as described in the tracing of these circuits.)

Assuming, for example, that the car is operated on a normal up trip, the relay 107 will be energized by way of a circuit which extends from line conductor L1 through conductor 100', the normally closed contact members of a switch UL, conductor 112, the contact members of an up release, button 113 (mounted on the car), conductor 114,. the normally closed contactmembeis 26a,- of relay 26, conductor 115, the coil of relay 107 and conductors 116 and 21 to line conductor L2. The relay 107 will remain energized until the car arrives at its upper limit of travel, and operates switch UL, at which time the relay 107 is deenergized and the relay 26 will be ener 'z'ed.

Suppose that, during t e upward trip, the attendant discovers that his car has assed a floor at which it is desired to stop t e car. He may reverse the car switch CS and bring the car back to the floor which was passed. That is, the car will reverse and travel downwardly at low speed only, since the circuit for high-speed operation is open at the contact members 107?). Thus, the car will travel at slow speed until it arrives adjacent the next lower floor, at which time the landing switch 38 will operate to stop the car level with the floor.

In modern high-speed elevators, operating at speeds between 600 and 900 feet per mlnute, the slow-down zone for any floor will extend through a distance which is greater than the distance between adjacent floors. Under these conditions, if a car is standing at one fioor, for example, the second floor, when a button is operated for the third floor, the car will not have sufiicient time, in passing between the adjacent floors, to attain hi h speed and then slow down for the third floor. To allow for this condition, the circuits for the high-speed switch 22 and the landing switch 38 lead through the contact members of all of the relays 33, 34, 35 and 36 and, in the event that any one of these relays is energized, as by the operation of one of the signal buttons at the floors or on the car, to cause the car to stop at the next adjacent floor, the speed relay is prevented from closing. Thus, the car will proceed to the next floor at slow speed only and will stop thereat in consequence of the operation of the landing switch 38.

It is thus seen that I have provided a control system which combines, in a single floor selector, the functions of controlling the stopping of the car in response to passengeroperated push-buttons, the restoration of the passenger-operated buttons, and the illumination of appropriate floor-landing lanterns at the floors, as the car prepares to stop thereat. My system also provides for permitting high-speed elevators having overlapping slow-down-zones, to receive signals for, and to stop at, adjacent floors and wherein the elevator will automatically operate at the proper speed to make such adjacent stops. 7

Figure 2 illustrates the manner in which additional cars may be connected to the floor push buttons 3U, 3D etc. and other associated relays whereb the control system described herein may lie applied to a bank of elevators. Figure 2 illustrates a car B having its controlling circuits and devices identical with those for car C. The connection of the control circuits for car B to those herein described for car C comprises merely the paralleling of conductors in groups 120, 121 and 122, respectively, to the corresponding contact strips and segments on floor selector FS associated with car B and, in like manner, to the floor selectors of as many other cars as may be in the bank. It will be observed that the conductors in group 120 are connected in parallel relation to the contact segments 3CU and 2CU to supply current to resetting of restorin relays 3US and 2US, respectively, and, in li e manner, to the corresponding contact segments on the down side of the floor selector F S to complete circuits for resetting relays 3DS and 2DS, respectively. Conductors 121 are connected in parallel relation with contact segments 3AU, 2AU, 2EU and 3EU, respectively, for supplying current to respective contact segments on the floor selectors for other cars in the bank when the associated push-button relays 3UR etc. have been energized. Conductors in group 122 are connected in parallel relation with contact segments 3AD, 2AD, 3ED and 2ED for connecting similar contact segments on the floor selectors for each of the cars in the bank to control their respective circuits when the push-button relays 3DR and 2DR are energized.

It will be readily observed, therefore, that my system is applicable to a plurality of elevator cars constituting a bank of adjacent elevators.

My system also provides for the automatic stopping of the car from Within it, as by the push-buttons C2 and C3, so connected that only one set of buttons is necessary for both up and down movements of the elevator.

The embodiment of my invention disclosed herein is merely illustrative, the apparatus and circuits involved being capable of adaptation to varied conditions of service involving different numbers of elevators and an indefinite number of floors served by the ele- ,vators.. My invention is applicable to any type of control systems for elevator motors, such as the Ward-Leonard type, or the rheostatic type of control. Therefore, I do not desire to be limited to the details of the system shown, except as defined in the appended claims.

I claim as my invention:

1. In a control system for elevators, a car operated between two terminal floors, a plura'nty of intermediate floors, multi-speed means for moving said .0111 in either direction, means for controlling the direction and speed of said moving means, and means responsive to the initial operation of said moving means in one direction for preventing said moving means from operating at greater than its lowest speed in reversed movement until said car has reached the terminal floor in the first direction.

2. In a control system for elevators, a car operated between two terminal floors and a plurality of intermediate floors, multi-speed means for moving said car in either direction, means for controlling the direction and speed of said moving means, and means responsive to theinitial operation of said moving means in one direction for preventing said moving means from operating at greater than its lowest speed in reversed movement until said car has reached the terminal floor in the first direction, and means for automatically stopping said elevator at the landing next approached in said reverse direction.

In testimony whereof, I have hereunto subscribed my name this 2lst day of June, 1927.

FRANK E. LEWIS. 

